Introduction

I've been asked from time to time why we've never reviewed any of Drobo's NASes. The story is I've tried, but company management was reluctant to submit their NAS for review, fearing its performance would not compare favorably. Yes, we could have purchased the product and reviewed it, but other priorities always got in the way.

Drobo's new management that took over when Drobo was spun off from Connected Data in 2015, however, has no such fears. So when they were ready to launch an updated version of the 5 bay Drobo 5N, they reached out and readily offered a sample for review.

The 5N2 looks very much like the model 5N it replaces, housed in a sturdy aluminum black matte finish box. The only external clue that you're looking at a 5N2 is the two Gigabit Ethernet ports on the rear panel. The 5N2 retains the 5N's carrier-less drive bay design; you just slide drives right in. The tradeoff for eliminating drive trays is that only 3.5" SATA drives are supported for direct insertion. If you want to use 2.5" drives, Drobo recommends Icy Dock's EZConvert Pro MB982SP-1S. But at around $25 a pop, you may decide to stick with good ol' hard drives.

Drobo 5N2 callouts

Making that choice a bit easier is the Drobo Accelerator bay on the bottom, which holds one mSATA SSD. Inserting the drive activates a "hot cache". Drobo says this will help most with workloads that contain a random read component, for example, loading a Lightroom library. My Drobo contact said typical performance gain may be in the 20 - 30% range, once the cache has had time to "heat up", i.e. be loaded with commonly accessed data.

Drobo 5N2 "Accelerator bay"

Other than the dual Ethernet ports and mSATA bay, the 5N2 lacks features available on even entry level NASes. There are no USB or eSATA ports for attached backup or printer sharing; no HDMI ports to play content to an attached screen. There's not even a buzzer to signal shutdown start, boot-up end or alert situations.

The drive lights do blink when something unusual is going on with the drives, however, such as volume rebuilds or drive faults. Drobo puts a convenient LED decoder right on the inside of the front cover. There is also a set of blue capacity LEDs on the front panel too; each one indicates 10% of used capacity.

Drobo 5N2 LED decoder

Inside

Disassembly took a bit of figuring out after easily removing the outer shell. After that, it took a little poking to get it down to the view shown below, showing the five drive bays and the main board sitting on the bottom of the case.

Drobo 5N2 inside, view into drive backplane

Flipping the view around reveals the battery that provides power for long enough to write pending data to disk and cleanly shut down.

Drobo 5N2 inside, behind drive backplane

Removing the main board and taking off the heatsink reveals the 5N2 is powered by a Marvell quad core Armada XP ARMv7 CPU @ 1.6 GHz.

Drobo 5N2 board top

The bottom of the board has the mSATA cache SSD slot. That's the second Marvell 88E1318-NNB2 Gigabit Ethernet PHY at upper left beside the mSATA slot.

Table 1: Key component summary

The 5N2 drew 35 W with four of our stock WD Red 1 TB (WD10EFRX) drives spun up and 21 W in power save mode with the drives spun down. Fan and drive noise was rated very low, running whisper quiet in our low-noise home office.